Department of Mathematics Education

# EMAT 6700, J. Wilson

Wasting Water

J. Matt Tumlin

Wasting Water is an activity in which students gather data to find a trend.  Students are asked to make a scatter plot of the amount of water leaked by time and approximate a line of best fit.  Then they research the same set of data with Excel spreadsheet and find a linear equation that models it.

To motivate the students, discuss a faucet dripping.  Ask students what amount of water is lost.  Ask students what they think will happen when the water leaks through the cup.  Do they think the amount of water that is leaking through the cup will increase, decrease, or stay the same?  Do they think there will be a time when the amount of water will level off?

## Directions

The materials you will need are paper cups, paper clips, graduated cylinders, timers, and handouts.  You can have the students work in groups of three.  One person will record the data, one person holds the cup over the graduated cylinder and at the beginning of the experiment, makes a hole in the bottom of the cup, and one person reads the measurement in five second intervals.  Pour water into the cups, make a hole in the bottom, and hold your finger over the hole until the experiment begins.  When the timer says to begin, remove your finger and let the water start dripping.  BE PREPARED!  Every five seconds, measure the water level in the graduated cylinder and record the data in the table.  At the end of 60 seconds the experiment is over.  Make sure you have recorded all of the data in the table.  Pour any remaining water into the graduated cylinder.  Graph and analyze your data using Excel and make predictions.

Using Excel spreadsheet is optional.  In higher classes, the students should be familiar with Excel.  In lower classes, this would be a good way to introduce it.  Be sure the students understand that the computer uses a well-defined algorithm, so there will be only one right answer.